Navien Error Code E291: Cascade Communication Error
Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost:$100 — $350(parts + labor)
Warning: Your Navien boiler's cascade communication is experiencing an error, which may impact its performance and efficiency. It's safe to troubleshoot, but if the issue persists, contact a professional.
How to Fix Navien Code E291
Check if the cascade module is securely connected and powered
Ensure the module's configuration matches your boiler's settings
If the issue persists, try resetting the boiler and the cascade module
How to Reset Navien Code E291
Turn off the unit using the power button on the front panel.
Turn off the gas supply valve.
Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
Restore power at the breaker, then open the gas valve.
Turn the unit back on. If the error returns, the underlying issue needs repair.
What does E291 mean?
The E291 error on your Navien boiler indicates a cascade communication issue between the boiler and its optional cascade module. This error doesn't pose an immediate safety risk, but it's important to address it to maintain optimal system performance. The cascade module allows multiple boilers to operate together, and this error suggests there's a problem with this communication.